update dsfield file values

Update the rt_dsfield file to contain values defined in current RFC.
The days of TOS precedence are gone, even Cisco doesn't refer
to these in the documents.

etc/iproute2/rt_dsfield

-0x00	default
-0x10	lowdelay
-0x08	throughput
-0x04	reliability
-# This value overlap with ECT, do not use it!
-0x02	mincost
-# These values seems do not want to die, Cisco likes them by a strange reason.
-0x20	priority
-0x40	immediate
-0x60	flash
-0x80	flash-override
-0xa0	critical
-0xc0	internet
-0xe0	network
+# Differentiated field values
+# These include the DSCP and unused bits
+0x0	default
 # Newer RFC2597 values
 0x28	AF11
 0x30	AF12
@@ -25,3 +14,12 @@
 0x88	AF41
 0x90	AF42
 0x98	AF43
+# Older values RFC2474
+0x20	CS1
+0x40	CS2
+0x60	CS3
+0x80	CS4
+0xA0	CS5
+0xC0	CS6
+0xE0	CS7
+0x5C	EF